Experiments are in progress to characterize the surface polypeptides of the herpes simplex virion (HSV). Surface polypeptides have been identified by iodination of purified, enveloped HSV particles with 1,3,4,6-tetrachloro-3 alpha, 6 alpha-diphenyglycoluril and Na125I, followed by SDS-polyacrylamide gel electrophoresis and autoradiography. Surface carbohydrate moieties have been identified by assaying for the presence or absence of agglutinated virus after purified virus had been mixed with individual lectins each with a particular sugar specificity. To determine whether a particular sugar residue is functionally important, sugar moieties identified with lectins will be enzymatically removed by treatment of purified HSV with the appropriate glycosidase, after which the treated virus will be tested for infectivity. Surface polypeptides of the HSV envelope, which have been identified by iodination will be purified and monospecific antiserum will be prepared against each purified polypeptide. Monospecific antiserum will be used as probes to the function of the HSV envelope polypeptides.